Top down control takes some time off as words start to flow.

At Ars, we’ve seen tears and faux tarantulas inside fMRI machines, but here’s a new one: rappers. A group of researchers from NIH wanted to investigate what goes on in the brain during periods of intense creativity, and what’s a better example of pure improvisation than freestyle rapping? So the researchers—along with two rappers/co-authors—ran a group of freestylers through an fMRI machine and reported their results in this week’s Scientific Reports.

Twelve male rappers, all of whom had at least 5 years of professional experience, took part in the study. The same 8-bar background track was used for all the experiments; in the “conventional” condition, the participants were asked to memorize lyrics given to them a week before the experiment. In the “improvised,” or freestyle, condition, the rappers had to come up with lyrics on the spot—or, rather, in the tube. Each participant was scanned in an fMRI machine under both the “conventional” and the “improvised” conditions to determine how brain activity differed between these two types of performances.

One of the major differences between the improvisational and the rehearsed rap was that those who were freestyling had increased activity in the medial prefrontal cortex (MPFC) and decreased activity in the dorsolateral prefrontal cortex (DLPFC), compared to those that were rapping verses they had practiced. In general, the MPFC provides signals to the DLPFC, where the information is processed and passed along to the rest of the body.

The DLPFC, therefore, can act as a filter and has executive control over what eventually reaches the motor system. During freestyling, however, it appears that this control system is muted, allowing flexibility and creativity to blossom without being stifled or double-checked.

The fMRI results suggest that, while improvising, rappers enter a “flow” state that is similar to athletes being "in the zone.” Several parts of the brain involved in sensory experience—including the amygdala, the inferior parietal lobules, and the insulae—are activated and connected, helping the rapper become immersed in the performance, and potentially fostering creativity.

The researchers also found that brain activity during freestyles changes across time, possibly due to differing demands at various parts of the rap. At the beginning of an improvised 8-bar segment, activity peaked in the left half of the brain. However, by the last measure of each 8-bar segment, activity in the right half of the brain was peaking. This may be due to differing cognitive demands at these different parts of the rap; at the beginning of a segment, language and creativity may be of the utmost importance, but by the end of the verse, a rapper might need to rely more on a rule-based approach in order to ensure proper rhyme and rhythm.

As an interesting side note, each rapper was given a language test before the experiment that assessed their linguistic skills; all twelve participants scored above the 80th percentile. It’s not too surprising that these guys are whizzes with language, when you consider the incredible linguistic demands of freestyling.

Although the study was largely exploratory and the researchers didn't test any explicit hypotheses, the study offers interesting insights into the neural underpinnings of improvisation and the creative process. It’s clear that different areas of the brain are activated during freestyle compared to rehearsed rap; in fact, entire neural networks emerge during improvisation, inhibiting self-control and affecting emotional state, two changes that may foster and improve creativity.

While some other types of musicians, such as jazz pianists, have undergone fMRIs to investigate improvisation, the jury is still out on whether similar process underlie creativity in non-musical artistic pursuits, or in spontaneity in our day-to-day life.

Kate Shaw Yoshida / Kate is a science writer for Ars Technica. She recently earned a dual Ph.D. in Zoology and Ecology, Evolutionary Biology and Behavior from Michigan State University, studying the social behavior of wild spotted hyenas.